Properly use proper subtyping for callables

[ilevkivskyi]

Fixes #16338

This is kind of a major change, but it is technically correct: we should not treat (*args: Any, **kwargs: Any) special in is_proper_subtype() (only in is_subtype()). Unfortunately, this requires an additional flag for is_callable_compatible(), since currently we are passing the subtype kind information via a callback, which is not applicable to handling argument kinds.

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

porcupine (https://github.com/Akuli/porcupine): typechecking got 1.41x slower (30.7s -> 43.3s)
(Performance measurements are based on a single noisy sample)

comtypes (https://github.com/enthought/comtypes)
+ comtypes/client/_events.py:116: error: All conditional function variants must have identical signatures  [misc]
+ comtypes/client/_events.py:116: note: Original:
+ comtypes/client/_events.py:116: note:     def error_printer(self: Any, this: Any, *args: Any, **kw: Any) -> Any
+ comtypes/client/_events.py:116: note: Redefinition:
+ comtypes/client/_events.py:116: note:     def error_printer(*args: Any, **kw: Any) -> Any

discord.py (https://github.com/Rapptz/discord.py)
- discord/app_commands/commands.py:2381: error: Item "function" of "Callable[[Any, Interaction[Any], VarArg(Any), KwArg(Any)], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], VarArg(Any), KwArg(Any)], Coroutine[Any, Any, Any]]" has no attribute "__discord_app_commands_checks__"  [union-attr]
+ discord/app_commands/commands.py:2381: error: Item "function" of "Callable[[Any, Interaction[Any], VarArg(Any), KwArg(Any)], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], VarArg(Any), KwArg(Any)], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], Member], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], User], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], Message], Coroutine[Any, Any, Any]]" has no attribute "__discord_app_commands_checks__"  [union-attr]
- discord/app_commands/commands.py:2383: error: Item "function" of "Callable[[Any, Interaction[Any], VarArg(Any), KwArg(Any)], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], VarArg(Any), KwArg(Any)], Coroutine[Any, Any, Any]]" has no attribute "__discord_app_commands_checks__"  [union-attr]
+ discord/app_commands/commands.py:2383: error: Item "function" of "Callable[[Any, Interaction[Any], VarArg(Any), KwArg(Any)], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], VarArg(Any), KwArg(Any)], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], Member], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], User], Coroutine[Any, Any, Any]] | Callable[[Interaction[Any], Message], Coroutine[Any, Any, Any]]" has no attribute "__discord_app_commands_checks__"  [union-attr]

[JukkaL]

Again, thanks for the quick fix! It's interesting that this wasn't noticed earlier.

The impact doesn't look huge based on mypy_primer, though can you have a look at the output from comtypes before merging?

[hauntsaninja]

comtypes primer hit looks correct, reveal_type(func(spam)) in the test changing seems a little unfortunate

[ilevkivskyi]

Yes, the new error in mypy_primer is correct.

@hauntsaninja The Any in overload test actually doesn't worry me. This is quite a weird test, if you look at the commit history for this test, you will see something changes there quite often. TBH I am not even sure what this test is supposed to test, and what is a desired result there.